DNSBLs and Securence Part 1: Securence’s Use of DNSBLs

DNSBL stands for DNS Block List. Also called RBL for Realtime Block List. These acronyms have had different words at times, but they generally do the same thing: prevent emails based on the IP address of the sending server.

Securence, by default, uses two of our own private DNSBLs and two independent DNSBLs to block messages based on IP address.

rbl.securence.com is a realtime block list, listings are fully automated and extremely short lived. Listings are intended to exist during a spam outbreak and expire as soon as the behavior stops. This uses a yellowlist to prevent blocking the major email senders. Though our support department has a delisting process, blocks have typically expired by the time our support department receives any delisting request.

bl.securence.com is a non-realtime block list. This is a very small list of addresses and is manually curated by our email staff. Candidates are personally researched before listing to ensure no clean emails are originating from these addresses. Generally, listings do not expire. Though our support department has a very simple delisting process available, we have never received a delisting request.

Securence has subscriptions for Spamhaus and Spamcop. These lists are served from our internal servers and updated frequently from the providers. These are enabled by default for new domains and we recommend our customers to use both. They have their own processes and procedures that can be found on their respective web sites.

Securence can be configured to use any standard DNSBL in the admin portal. If you have a DNSBL you would like to use, go to Domain Settings->IncomingSettings->Spam->DNS Block Lists->Other DNS Block Lists or ask our support staff for assistance.